This invention relates to liquid crystal devices, and particularly to means for making electrical connections to the electrodes of such devices.
One known type of liquid crystal cell comprises a pair of oppositely disposed, spaced apart substrates having a liquid crystal material sandwiched therebetween. Each substrate has an electrode on the inside surface thereof, and the cell is turned on by applying a voltage between the electrodes.
To make electrical connections to each of the electrodes, metallized paths are provided on the inside surfaces of the substrates extending between the electrodes and edge portions of the substrate where terminal connections are made.
To provide access to the substrate inside surfaces at the substrate edges, it is the practice to extend an edge portion of each substrate beyond the corresponding edge of the other substrate. For example, if the cell comprises upper and lower substrates, on one side of the cell the lower substrate extends beyond the edge of the upper substrate, thereby exposing a portion of the inside surface of the lower substrate, while on another side of the cell, an edge portion of the upper substrate extends beyond the edge of the lower substrate, thereby exposing a portion of the inside surface of the upper substrate. Thus, terminal connections can be made to metallized paths which terminate at the exposed portions of the substrates at the two sides of the cell.
To simplify mounting and socketing of the cell, it is sometimes preferred that all the terminal connections be made to a single side only of the cell and to one only of the substrates. To accomplish this, it is necessary that an electrical connection be provided between the electrode on the other substrate and the portion of the one substrate to which the terminal connections are made.
An object of this invention is to provide such connection in a simple, reliable, and inexpensive manner.